(1) Field of the Invention
The present-invention relates generally to heaters for diving suits. More particularly, this invention relates to a portable catalytic heater relying on catalytic combustion of hydrogen to heat circulating water for a diving suit.
(2) Description of the Prior Art
The necessity for providing heat for both active and inactive divers during long duration, cold-water operations in swimmer delivery vehicles is well established. One documentation in support of this need is presented by M. W. Nuckols et al. in their article xe2x80x9cActive Diver Thermal Protection Requirement for Cold Water Divingxe2x80x9d J. Aviation, Space and Environmental Medicine, Vol. 54, No. 7 pp 644-648 (1983). Alternative approaches to supply this requirement for active heating have covered a wide range of technologies, including thermoelectric heaters, heaters using magnesium combustion such as the heater referred to as the Conox, propane/catalytic heating, and heating by direct electrical resistive means. While all of these methods have been shown to be capable of producing sufficient quantities of heat, each has its own inherent restrictions and interface issues when applied to diving operations involving swimmer delivery vehicles. Most prominent of these issues are the requirements of consumption of power for a heater that compete and detract from the power requirements for propulsion of the swimmer delivery vehicle. Another prominent issue is the requirement for packaging the heater for environments that are limited in space.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for a heater for a diving suit that provides a safe, reliable source of warm water for active thermal protection of divers over a wide range of diving applications.
One form of a catalytic heater has an insulating housing closed at opposite ends by cap members to define a chamber containing a catalyst inside of a multi-tube heat exchanger. Fittings in the cap members pass circulating water through the multi-tube heat exchanger to and from a diver""s suit, and a gas circuit flows mixed hydrogen and oxygen to the catalyst that reacts with the mixed hydrogen and oxygen to produce heat that heats the water in the multi-tube heat exchanger for the diving suit.
An object of the invention is to provide a compact heater to provide heated water for a diving suit.
Another object of the invention is to provide a safe, reliable source of warm water for active thermal protection of divers over a wide range of diving applications.
Another object of the invention is to provide a catalytic heater capable of being used in open, closed or semi-closed circuit configurations to support tethered diving applications, autonomous self-contained applications by free-swimming divers, or life support systems within wet or dry underwater swimmer delivery vehicles.
Another object of the invention is to provide a catalytic heater providing adjustment of temperature of circulating heated water by regulating the percentage of hydrogen injected into its catalyst bed.
Another object of the invention is to provide a compact catalytic heater that can be used either as the primary active heating source or as a backup heating system if failure occurs in the primary heat source.
Another object of the invention is to provide a catalytic heater that facilitates reaction of hydrogen with a small amount of oxygen in a gas mixture to produce heat transferred through a multi-tube heat exchanger to a circulating liquid that carries this heat to the diver.
Another object of the invention is to provide a catalytic heater having rates of production of heat that can be increased while using the same gas mixture by operating at elevated pressures.
Another object of the invention is to provide a catalytic heater having rates of production of heat increased by using carrier gases other than air, such as using a helium and oxygen gas mixture.
Another object of the invention is to provide a catalytic heater recirculating the gas mixture used to heat circulating water to increase efficiency.
Another object of the invention is to provide a catalytic heater having its heating capacity easily controlled with a simple mechanical metering valve for the hydrogen.
Another object of the invention is to provide a catalytic heater that does not require an active heating source.
Another object of the invention is to provide a catalytic heater that continues to provide heating of the whole body as long as hydrogen is present in the gas mixture.
Another object of the invention is to provide a catalytic heater that provides water vapor as a by-product of the reaction to possible help humidify breathing gases.
Another object of the invention is to provide a catalytic heater controlling water temperatures by simply adjusting the percentage of hydrogen passing through the catalyst bed.
Another object of the invention is to provide a catalytic heater having operational costs that are a fraction of the cost of batteries used in conventional electrical resistive heating systems.
These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.